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(Rd Model.)

' D. PARKHURST.

Y HEAD BLOCK. No. 274,366. Patented Max-20,1883.

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' Unrrnn STATES twice,

DARIUS PARKHURS'I, OF SI; LOUIS, MISSOURI, ASSIGNOR OF QNE-HALF TOGEORGE E. KNIGHT, OF SAME PLACE.

HEAD-BLOCK.

SPECIFICATION forming part of Letters Patent No, 274,366, dated March20, 1883.

Application filed December 5, 1882. (No model.)

To all whom it may concern Be it known that I, DARIUS PARKHURST, of thecity of St. Louis, in the State of Missouri. have invented a certain newand useful Improvement in Head-Blocks for Saw- Mills, of which thefollowing is a full, clear, and exact description, reference-bein g hadto the accompanying drawings, forming part of this specification, and inwhich Figure 1 is a top view. Fig. 2 is a side elevation. Fig. 3 is anenlarged top view, and Fig. 4 is a detail view of a modification.

I have shown my invention applied to the head-block for which patentissued to myself and assignee April 25, 1882; but it may he applied toany head-block.

Myinvention consistsin features of noveltypointed out in the claims.

Referring to the drawings, A represents th main shaft, and B thecounter-shaft, on the latter of which are the operating parts of theset-works. The shafts are journ aled in a suitable frame, 0. As mypresent invention does knees-that is to say, if the wheel is turnednntilthe figure 2 comes to the position figure l had occupied, the knees willhave moved back one inch.

F is a finger or pointer, secured by one end 4 to the frame 0 or to anyother suitable object, the other end of which works in the groove E asthe wheel turns. Th us, when the finger is at the numeral 1, the kneesare one inch back from the saws, and so on. I prefer using aspring-finger which would be rigidly secured to the frame, the springallowing the finger to remain in the spiral groove as the wheel turns;but instead of the finger springing it may he so secured'to the frame orother I object as to move, allowing it to remain in 0 the groove of thewheel. The groove maybe marked oil into sections of greater or lessdistance than that shown and described, if desired.

In Fig. at is shown a modification of the wheel D, wherein it consistsof a band cast upon or secured'to the arms of the fly-wheel G on the endof the shaft 13. I have made the wheel of such a size that onerevolution indicates eight inches movement of the knees, as the figureswill show; but this size is not essential. I

The operation is as follows: Supposing the last cut of a log has beenmade, the next thing, of course, to be done is to run the knees 6-5 backto allow the next log to be rolled onto the carriage against the knees.The sawyer, by glancing at the log, can ascertain very closelyits-diameter. He then runs the knees back until the desired number onthe wheel D comes to the fingeras, for instance, if he judges the log tobetwo feet in diameter, he turns the wheel D until the numeral 24 cameto the finger, or, it he wanted to take, say,

a. three-inch slab off the log, he would stop the wheel at thenumeral21, and soon; or, instead of the sawyer or operator guessing atthe size of the log, its exact diameter may have been ascertained bymeasuring.

Instead of the wheel l) having the spiral 8o groove E, it may have aspiral rib, when the end of the finger F would have a notch to fit overthe rib,and the same result would he had.

I am' aware that head-blocks have been pro vided with an indicator-wheelhaving aspiral groove, and a sliding rod carrying an indicater-fingerworking in said groove has been before known.

I claim as my invention--- l. The spring-pointer secured to the main 0frame, in combination with a spirally-grooved indicatorwheel of ahead-block for saw-mills, as set forth.

2. In a headblock for saw-mills, a Wheel secured to the o'ierating-shaft of the set-works 5 and provided with a spiral groove andscale, in combination with a stationary spring finger or pointerarranged to follow in the groove of the wheel, substantially as and forthe purto the. frame A and. its other end working in pose set forth. thegroove E of the wheel D, substantially as 3. In a head-block forsaw-mills, the combiand for the purpose set forth. nation of frame A,shaft B, wheel D, secured DARIUS PARKHURST. 5 to the shaft B, and havinga circumferential Witnesses:

spiral groove, E, and a suitable scale, and the G. B. TIRRELL, springfinger or pointer F, secured by one end A; L. GBOGKER;

